California Gov. Gavin Newsom signed a bill into law Monday prohibiting school boards across the state from banning books, instructional materials or curricula categorized as inclusive or diverse.

Under the new law, which went into effect immediately after its signing, the state can fine schools that would block textbooks and library books that allow students to learn about diverse communities.

The bill — formally known as AB 1078 — also authorizes Tony Thurmond, state superintendent of public instruction, to purchase instructional materials for school districts, regain costs from the purchases and determine whether to fine school boards if they do not abide by the state's updated instructional standards.

Newsom called the new measure "long overdue," emphasizing that the banning binge of materials needs to come to an end.

"Remarkable that we're living in a country right now in this banning binge, this cultural purge that we're experiencing all throughout America, and now increasingly here in the state of California, where we have school districts large and small banning books, banning free speech, criminalizing librarians and teachers," Newsom said in a video posted to X, formerly known as Twitter.

"We want to do more than just push back rhetorically against that, and that's what this legislation provides," he added.

Thurmond, who announced Tuesday he's running for governor in 2026, said the new law sends a "strong signal" to Californians that books should not be banned in the state.

"Rather than limiting access to education and flat out banning books like other states, we are embracing and expanding opportunities for knowledge and education because that's the California way," Thurmond said in a news release.

On Tuesday, Newsom signed a new law that doubles taxes on guns and ammunition in the state, using the tax money to fund more security at public schools along with various violence prevention programs.

The California law imposes an 11% tax in addition to the federal tax of 10% or 11%, depending on the type of weapon.

The book-ban law comes as school book bans and restrictions across the U.S. increased by 33% in the last school year, according to a new report by PEN America.

The free speech group said it found 3,362 cases of book bans — an increase from 2,532 bans in the 2021-22 school year.

The majority of the book bans came disproportionately from Florida, which accounts for more than 40% of book bans in the last school year — or 1,406 instances. Texas was next with 625, followed by 333 in Missouri, 281 in Utah and 186 in Pennsylvania.